Intermittent Slip Along the Alto Tiberina Low‐Angle Normal Fault in Central Italy
Alessandro Vuan, Piero Brondi, Monica Sugan, Lauro Chiaraluce, Raffaele Di Stefano, Maddalena Michele
Abstract
Abstract The Alto Tiberina normal fault (ATF) in central Italy is a 50‐km‐long crustal structure that dips at a low angle (15–20°). Events on the fault plane are about 10 times less frequent than those located in its shallower syn‐ and antithetic hanging‐wall splays. To enhance ATF catalog and achieve a better understanding of the degree of coupling in the fault system, we apply a template matching technique in the 2010–2014 time window. We augment by a factor 5 the detections and decrease the completeness magnitude to negative values. Contrary to what previously observed on ATF, we highlight intermittent seismic activity and long‐lasting clusters interacting with sequences on the shallower splays. One of these episodes of prolonged seismic activity, detected at the end of 2013 on a 30‐km‐long ATF segment, suggest the ATF active role during an aseismic transient unraveled by geodetic data.